Automotive coolant control valve

ABSTRACT

A coolant flow valve for controlling the distribution and flow of coolant to replace the radiator thermostat and heater valve currently used in automotive applications. The valve includes a valve rotor rotationally received in a valve housing wherein the rotational orientation thereof determines which combination of flow paths through four different outlet ports is selected.

BACKGROUND OF THE INVENTION

[0001] The present invention generally relates to a valve forcontrolling the flow of fluid and more particularly pertains to a valvefor simultaneously controlling the distribution and flow of anautomobile's coolant through multiple flow paths.

[0002] Water-cooled internal combustion engines that are used inautomobiles rely on a fluid to carry excess heat from the engine to anexternal heat exchanger commonly referred to as the radiator. Suchcoolant is continuously recirculated through the engine until itstemperature exceeds a preselected level at which point a portion of theflow is routed through the heat exchanger. The flow to the radiator iscontinuously adjusted in order to maintain the temperature of thecoolant within a desired range. The heat carried by the fluid is alsoused to heat the interior of the automobile whereby a portion of thecirculating coolant is routed through a second heat exchanger positionedso as to heat air that is directed into or recirculated within thepassenger compartment.

[0003] The distribution of the flow of coolant that is generated by anengine-driven water pump is typically controlled by two separatecomponents, namely a radiator thermostat and a heater valve. Heretoforeused thermostats typically rely on a mechanism that causes the forcegenerated by the expansion of mass of wax-like material to overcome thebias of a spring to open a valve wherein the wax-like material expandsas a function of temperature. The entire device is immersed in the flowof coolant and is positioned and configured so as to block off the flowof coolant to the radiator when the valve is closed. While the valve isin its closed position, the coolant continues to circulate but is forcedto bypass the radiator and is redirected back into the engine's waterpassages. A number of disadvantages are associated with this type ofconfiguration including, but not limited to, the fact that the bypassflow path remains open at all times and that a portion of the flow ofcoolant therefore always bypasses the radiator even if maximum coolingis called for. Additionally, the positioning of the thermostat directlyin the flow path of the coolant poses an impediment to the flow ofcoolant and thereby compromises the efficiency of the cooling systemwhile the failure of the opening mechanism typically results in thethermostat remaining in its closed configuration which can quickly leadto engine damage. Another disadvantage inherent in heretofore usedthermostat configurations is the fact that the device can necessarilyonly respond to the temperature of the coolant rather than directly tothe temperature of the engine, let alone the anticipated cooling needsof the engine. The engine temperature may therefore not necessarily beoptimized for a variety of conditions which may result in decreased fuelefficiency and increased exhaust emissions.

[0004] Heater valves are typically positioned so as to direct a portionof the flow of coolant to a heater core positioned within the HVACsystem of the automobile. Early heating systems included a valve thatwas simply actuated by a cable extending from a lever positioned in theinterior of the automobile. Many modern systems employ computercontrolled servo operated valves, wherein the valve position is eithermodulated so as to control the temperature of the heater or subject toeither a fully open or fully closed position wherein air heated by theheater is subsequently mixed with cooled air to regulate the temperaturewithin the passenger compartment.

[0005] A difficulty associated with this heretofore approach towardcontrolling the flow and distribution of coolant is inherent in the factthat, in effect, two independently operating systems are affecting thetemperature of a common coolant. A change in the demand for heat withinthe passenger cabin will effect the temperature of the coolant as willthe position of the thermostat. A change in one will necessarily inducea change in the other and without a common control system, thetemperature may tend to fluctuate and dither. Variations in engine load,especially in for example in stop-and-go traffic will introduce evenmore fluctuation as the heat fed into the system will additionally besubject to variation. Increasingly strict emission regulations anddemands for higher fuel efficiencies require the engine to operate innarrower temperature ranges which requires a more precise control ofcoolant temperature. An improved cooling system is needed with whichcoolant temperature and hence engine and heater temperature can be moreprecisely controlled.

SUMMARY OF THE INVENTION

[0006] The valve of the present invention overcomes the shortcomings ofpreviously known coolant flow and distribution control systems. A singlevalve replaces the presently used separate thermostat and heater valvedevices and provides for the comprehensive control of the routing andflow of circulating coolant. The valve controls the flow of coolant tothe radiator, the amount of flow that bypasses the radiator to bereintroduced into the engine's cooling passages, the flow of coolant tothe heater and additionally provides for the degassing of the coolantflowing through the valve. All such functions are achieved by a singlevalve as described herein.

[0007] The valve of the present invention includes a valve rotor that isrotationally received within a valve housing. The housing includes aninlet and a number of outlet ports formed therein while the valve rotorhas a number of conduits extending therethrough that serve to set theinlet port into fluid communication with a selected combination ofoutlet ports as a function of the rotational orientation of the valverotor within the valve housing.

[0008] More particularly, the valve of the present invention isconfigured such that the ports that are formed in the cylindrical valvehousing are arranged along at least two planes that are spaced along theaxis of the housing. A first plane may include the inlet port and anoutlet port for flow to the radiator. Ports arranged along a secondplane may include a heater outlet port and a bypass port. A port forcarrying gas bubbles may be formed in an end of the cylindrical housing.The conduits formed in the valve rotor are arranged such that selectedconduits become aligned with selected ports as a function of therotational orientation of the valve rotor within the valve housing. Aninternal conduit extends along the axis of the valve rotor so as tointerconnect conduits that arranged along the two planes.

[0009] The precise rotational orientation of the valve rotor within thevalve housing required to achieve a certain distribution and flow ofcoolant may be achieved by the operation of a stepper motor. Inputsreceived from one or more temperature sensors and from an operator withregard to a selected heater temperature may be interpreted by amicroprocessor to generate a signal necessary to drive the motor to adesired position. A mechanical spring may additionally be employed toforce the valve rotor to assume a rotational orientation for providingmaximum flow to the radiator and heater in the event a failure of theelectronics takes place to serve as a fail safe mode.

[0010] These and other features and advantages of the present inventionwill become apparent from the following detailed description of apreferred embodiment which, taken in conjunction with the accompanyingdrawings, illustrates by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a perspective view of a valve assembly that includes apreferred embodiment of the valve of the present invention;

[0012]FIG. 2 is a perspective view of the valve;

[0013]FIG. 3 is a perspective view of the valve rotor;

[0014]FIG. 4 is a cross-sectional view of the valve rotor taken alonglines 4-4 of FIG. 3;

[0015]FIG. 5 is a cross-sectional view of the valve rotor taken alonglines 5-5 of FIG. 3;

[0016]FIG. 6 is a bottom plan view of the valve rotor shown in FIG. 3;

[0017]FIG. 7 is an enlarged cross-sectional view taken along lines 7-7of FIG. 2;

[0018]FIG. 8 is a cross-sectional view of the valve rotor within thevalve housing taken along the same plane as illustrated in FIG. 4 androtated to its maximum counter-clockwise rotational orientation;

[0019]FIG. 9 is a cross-sectional view of the valve rotor within thevalve housing taken along the same plane as is illustrated in FIG. 5 andin the same rotational orientation of the valve rotor vis-a-vis thevalve housing as is shown in FIG. 8;

[0020]FIG. 10 is a cross-sectional view of the valve rotor within thevalve housing taken along the same plane as illustrated in FIG. 4 and inits maximum clockwise rotational orientation;

[0021]FIG. 11 is a cross-sectional view of the valve rotor within thevalve housing taken along the same plane as is illustrated in FIG. 5 andin the same rotational orientation of the valve rotor vis-a-vis thevalve housing as is shown in FIG. 10; and

[0022]FIG. 12 is a graphic representation of the various flow paths as afunction of rotational orientation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The valve of the present invention replaces a conventionalradiator thermostat and heater valve that are typically employed inmodern automobiles. The valve controls the flow and distribution ofcoolant to the radiator, radiator bypass and heater and may optionallycontrol the degassing of the coolant.

[0024]FIG. 1 is a perspective view of a valve assembly 12 that includesthe valve 14 of the present invention. The valve controls the flow ofcoolant therethrough, wherein coolant entering through inlet port 16 isdistributed via a preselectable combination of outlet ports 18, 20, 22,24. Setting the inlet port into fluid communication with a desiredcombination of outlets ports is achieved via the operation of anassociated drive mechanism 26 which may take the form of a stepper motorand reduction gear combination.

[0025]FIG. 2 is a perspective view of the valve 14 sans drive mechanism.The valve includes a valve rotor 28 that is rotationally received withina valve housing 30. The valve housing has a plurality of ports formedtherein, including an inlet port 16, a radiator port 18, a bypass port20, a heater port 22 and a degassing port 24. Each of the ports extendthrough the wall of the housing to define a conduit to its interior. Theaxis 32 of the inlet port and the axis 34 of the radiator port arealigned with one another and lie on a first plane that is perpendicularto the central axis 36 of the cylindrical valve. The axis 38 of thebypass port and the axis 40 of the heater port lie on a second planethat is perpendicular to the central axis wherein such second plane isaxially displaced relative to the first plane. The axis 42 of thedegassing port extends from the base of the valve housing, is generallyparallel to the central valve axis 36 and radially offset therefrom. Inthe embodiment illustrated, each of the ports has a length of barbedtubing 43, 44, 45 of appropriate length and diameter extending therefromconfigured for receiving a coolant carrying hose or line that may befitted and clamped thereto. The rotational orientation of the valverotor within the valve housing determines which outlet ports are setinto fluid communication with the inlet port. A shaft 46 extends fromone end of the valve rotor along its axis 36 to facilitate its rotationby the drive mechanism. A return spring 47 disposed about the shaftserves to bias the valve rotor into a preselected rotational orientationrelative to the valve housing.

[0026]FIG. 3 is a perspective view of the valve rotor 28 of the valve 14of the present invention. The valve rotor has a number of internal fluidpassages formed therein that are interconnected to one another withinthe interior of the valve rotor and to various openings 48, 50, 52formed on the surface of the valve rotor. The openings arecircumferentially as well as axially spaced relative to one another inprecisely defined locations so as to become aligned with selected portsformed in the valve housing 30 at preselected rotational orientations ofthe valve rotor relative to the valve housing.

[0027]FIG. 4 is a cross-sectional view of valve rotor 28 taken alonglines 4-4 of FIG. 3. Clearly visible is a T-shaped fluid passage 54formed therein that extends through the interior of the valve rotor andto its surface via openings 48, 50 and 56. A central fluid passage 58extends down along the central axis of the valve rotor. The rotationalorientation of the valve rotor within the valve housing 30 willdetermine which of the openings 48, 50 and 56 is to be set into fluidcommunication with radiator port 18 and what percentage of thecross-sectional area of such opening is to be aligned therewith.

[0028]FIG. 5 is a cross-sectional view of the valve rotor 28 taken alonglines 5-5 of FIG. 3. The pie-shaped fluid passage 60 serves to set thecentral fluid passage into fluid communication with the elongatedopening 52 formed on the surface of the rotor as well as with the smallaxially extending fluid passages 62, 64. The rotational orientation ofthe valve rotor within the valve housing 30 will determine whether thebypass port 20 or the heater port 22 or both ports are to be alignedwith all or a portion of opening 52.

[0029]FIG. 6 is a bottom plan view of the valve rotor 28 showing the twogrooves 66, 68 formed in the base of the component. The grooves are influid communication with fluid passages 62, 64 which extend into fluidpassage 60. The rotational orientation of the valve rotor within thevalve housing 30 will determine whether one of the grooves is set intofluid communication with the degassing port 24 formed in the base of thevalve housing.

[0030] Seals are fitted about each of the outlet ports so as to limitthe flow of fluid therethrough to only fluid that issues from an openingformed in the valve rotor 28 that is wholly or partially alignedtherewith. FIG. 7 is an enlarged cross-sectional view taken along line7-7 of FIG. 2 illustrating the seal configuration employed for heaterport 22 which is identical to that which is employed for the radiatorport 18 as well as the bypass port 20. Each of such ports includes asection of tubing 44 (or 43, 45) that extends outwardly and isconfigured for receiving and retaining a hose or other conduit clampedthereto. Each such section of tubing includes a neck portion 72 ofreduced diameter disposed near its proximal end that terminates so as tobe approximately aligned with the inner diameter of the valve housing30. A flexible seal 70 includes a collar 74 is tightly fitted about theneck portion as well as a flange 76 that engages the surface of thevalve rotor 28. The seal is configured such that the coolant which ispresent in the space 78 between the valve rotor and the valve housingserves to backload the seal so as to urge the flange against the valverotor and thereby form an effective seal. A simple O-ring (not shown)serves to form a seal about the proximal end of the degassing port 24. Asimple gasket (not shown) serves to form a seal between the upper flange80 of the valve housing and a cooperating surface that may extend fromthe enclosure for the drive mechanism. An additional O-ring (not shown)is fitted about shaft 46 to form a seal with a cooperating surface ofthe enclosure for the drive mechanism to complete the seal of the valvehousing.

[0031] In use, the valve of the present invention is plumbed such thatthe inlet port 16 receives the output from the water pump that is usedto circulate an engine's coolant. The pump may comprise an engine drivenor electrically driven device. The radiator port 18, bypass port 20 andheater port 22 are each plumbed to the respective components while thedegassing port 24 is plumbed so as to most advantageously remove bubblesfrom the circulating coolant as is appropriate for a particular coolingsystem such as by connection to an overflow tank. Conventional hoses andhose clamps may be used to make the various connections. Any of a widevariety of control configurations may be employed to rotate the valverotor 28 within the valve housing 30 in order to achieve a desiredeffect. A microprocessor receiving inputs from various sensors,including for example temperature sensors, as well as input from anoperator, including for example a desired cabin temperature setting,determines which rotational orientation of the valve rotor within thevalve housing would provide the appropriate amount of coolant flowthrough the various flow paths. The drive mechanism can then be providedwith the appropriate signal in order to rotate the valve rotor into theproper orientation.

[0032]FIGS. 8 and 9 are cross-sectional views of a preferred embodimentof the valve of the present invention wherein the valve housing 28 isrotated to its extreme counter-clockwise position within the valvehousing 30. FIG. 8 is a cross-sectional view along the plane thatincludes the axis 32 of the inlet port 16 and the axis 34 of theradiator port 18. FIG. 9 is a cross-sectional view along the plane thatincludes the axis 38 of the bypass port 20 and the axis 40 of the heaterport 22. Fluid entering inlet port 16 is free to enter the valve rotor28 through any of the unobstructed openings. While the most direct pathis via opening 48, the gap 78 between the valve rotor and the valvehousing also provides fluid paths to openings 50, 52 and 56. In thisparticular rotational orientation only a small percentage of one of theoutlet ports, namely radiator port 18 is aligned with openings (50, 56)formed in the valve rotor. Radiator port seal 82 prevents unobstructedflow along gap 78 into the radiator port while bypass port seal 84 andheater port seal 86 precludes any flow into the respective ports.

[0033]FIGS. 10 and 11 are cross-sectional views of a preferredembodiment of the valve of the present invention wherein the valvehousing 28 is rotated to its extreme clockwise position within the valvehousing 30 which represents a rotation of approximately 225 degrees fromthe rotational orientation shown in FIGS. 8 and 9. FIG. 10 is across-sectional view along the plane that includes the axis 32 of theinlet port 16 and the axis 34 of the radiator port 18. FIG. 11 is across-sectional view along the plane that includes the axis 38 of thebypass port 20 and the axis 40 of the heater port 22. Fluid enteringinlet port 16 is free to enter the valve rotor 28 through any of theunobstructed openings. While the most direct flow path is via opening56, the gap 78 between the valve rotor and the valve housing alsoprovides flow paths to openings 50 and 52. In this particular rotationalorientation an unobstructed flow path is provided to both the radiatorvia opening 48 and radiator port 18 and to the heater via central fluidpassage 58, opening 52 and heater port 22. Flow to the bypass port 20 iscompletely blocked off and sealed by bypass port seal 84. As such, thisrotational orientation provides for maximum engine cooling and is usedas a default or failsafe mode. In the event of a controller or otherelectrical malfunction, mechanical spring 47 serves to rotate the valverotor into this orientation.

[0034]FIG. 12 is graphic representation of the various flow paths thatare established as a function of the rotational orientation of the valverotor 28 within the valve housing 30. The horizontal axis represents therotational orientation of the valve rotor in degrees while the verticalaxis represents the approximate open area that is available for the fourdifferent outlets. The radiator outlet is denoted by diamonds, theheater by the squares, the bypass by the triangles and the degas by the“X's”. The cross-sectional illustrations of FIGS. 8 and 9 arerepresented by the 0 degree position while the cross-sectionalillustrations of FIGS. 10 and 11 are represented by the 225 degreeposition.

[0035] The valve configuration of the present invention allows a varietyof different flow path combinations to be selected, including:

[0036] a. Bypass only with Degas closed;

[0037] b. Heater only with Degas closed;

[0038] c. Heater and Bypass open with Degas open;

[0039] d. Bypass open with Radiator blended and Degas open;

[0040] e. Heater open with Radiator blended and Degas open;

[0041] f. Radiator blended from 10% open to 100% open with Degas open;and

[0042] g. Radiator open, Heater open, Degas open and Bypass closed.

[0043] A controller can be configured to select various rotationalorientations pursuant to various scenarios and conditions. Examples ofsuch scenarios and conditions and the corresponding orientationalselections include the following (wherein the index numbers correspondto the boxed numbers shown in FIG. 12): INDEX MODE RADIATOR HEATERBYPASS DEGAS Potential Cold Day Scenario 1 Warm up < 95° C. OFF OFF 100%OFF 2 Warm up = 95° C., OFF 100% OFF OFF before OEM Degas shutoff timeon Cold Day 3 Warm up > 95° C., after OFF 100% 100% 100% OEM Degasshutoff time on Cold Day 5 Transition on Cold Day  1% to 25% 100% OFF100% 7 Economy on Cold Day 35% to 80% 100% OFF 100% 9 Power on Cold Day 50% to 100% 100% OFF 100% 11  Engine Off/Overheat 100% 100% OFF 100%Potential Warm Day Scenario 1 Warm up < 95° C. OFF OFF 100% OFF 6Transition on Warm Day  1% to 25% OFF 100% 100% 8 Economy on Hot Day 35%to 80% OFF OFF 100% 10  Power on Hot Day  50% to 100% OFF OFF 100% 11 Engine Off/Overheat 100% 100% OFF 100%

[0044] The valve of the present invention may be formed from any of avariety of different materials. For example, the valve rotor maypreferably be formed of an acetal copolymer known as celcon while thevalve housing may be formed of a nylon thermoplastic. Other plastics mayalternatively be used. As a further alternative, a metal may be used inthe fabrication of one or both of the major components.

[0045] While a particular form of the invention has been illustrated anddescribed, it will also be apparent to those skilled in the art thatvarious modifications can be made without departing from the spirit andscope of the invention. The valve may be adapted for use in any of avariety of water-cooled engines, may be mounted in any of a variety ofspatial orientations, including but not limited to an invertedorientation, may used with any of a variety of devices for selectingrotational orientations based on a multitude of inputs while the valverotor may be rotated into position with any of a variety of drivemechanisms. Accordingly, it is not intended that the invention belimited except by the appended claims.

What is claimed is:
 1. A control valve for regulating the flow anddistribution of fluid therethrough, comprising: a valve housing havingan inlet port and at least three outlet ports; and a valve rotor,rotationally disposed within said housing and configured for settingselected combinations of said outlet ports into fluid communication withsaid inlet port as a function of the rotational orientation of saidvalve rotor within said valve housing.
 2. The control valve of claim 1,wherein said valve rotor has a rotational axis extending therethroughand said selected ports of said valve housing are aligned along twoaxially spaced planes that are perpendicular to said axis.
 3. Thecontrol valve of claim 2, further comprising a fourth outlet port formedin said valve housing align so as to be parallel with said rotationalaxis of said valve rotor.
 4. The control valve of claim 2, wherein saidinlet port and a first of said outlet ports are aligned along a firstplane of said two planes and a second and a third of said three outletports are aligned along a second plane of said two planes.
 5. Thecontrol valve of claim 4, wherein said inlet port and said first outletport are arranged so as to be colinear with one another on oppositesides of said valve housing.
 6. The control valve of claim 1, whereinsaid valve housing has a plurality of fluid passages formed thereinconfigured to interconnect a plurality of openings formed on its surfacethat are positioned so as to become aligned with selected ports formedin said valve body at selected rotational orientations of said valverotor within said valve housing.
 7. The control valve of claim 1,further comprising a spring for biasing said valve rotor to apreselected rotational orientation within said valve housing.
 8. Thecontrol valve of claim 1, further comprising an electric motor fordriving said valve rotor to selected rotational orientations within saidvalve housing.
 9. The control valve of claim 1, further comprising sealsdisposed about said outlet ports so as to form a seal between said valvehousing and said valve rotor.
 10. The control valve of claim 9, whereinsaid valve rotor and said valve housing are spaced apart so as to permitthe flow of fluid therebetween.
 11. A valve for distributing andregulating the flow of coolant issuing from a water pump to a radiator,a bypass circuit and a heater, comprising: a valve housing having portsformed therein including an inlet port configured to receive coolantissuing from a water pump, a first outlet port configured to directcoolant to a radiator, a second outlet port configured to direct coolantto a bypass circuit and a third outlet port configured to direct coolantto a heater; and a valve rotor rotationally disposed within said valvehousing configured to set said inlet port into fluid communication witha selected combination of said outlet ports.
 12. The valve of claim 11,further comprising an electric motor for driving said valve rotor intopreselected rotational orientations within said valve housing.
 13. Thevalve of claim 11, wherein said valve inlet port and said radiator portare formed in diametrically opposed locations in said valve housing andsaid valve rotor has a first fluid passage formed therein configured tobecome aligned with said inlet port and said radiator port at apreselected rotational orientation so as to provide a linear andunobstructed flow path for coolant through said valve.
 14. The valve ofclaim 13, wherein said bypass port and said heater port are arranged soas to define a plane perpendicular to a rotational axis of said valverotor and wherein such plane is axially spaced from said inlet andradiator ports.
 15. The valve of claim 14, wherein said valve rotor hasfluid passages formed therein that allow said inlet port to be set intofluid communication with said radiator port and said heater port whileblocking flow to said bypass port.
 16. The valve of claim 15, furthercomprising a spring for biasing said valve rotor to a rotationalorientation wherein said inlet port is set into fluid communication withsaid radiator port while blocking flow to said bypass port.
 17. Thevalve of claim 16, wherein said rotational orientation further serves toset said inlet port into fluid communication with said heater port. 18.The valve of claim 14, wherein said valve rotor has fluid passagesformed therein to allow said inlet port to be set into fluidcommunication with said radiator port while blocking flow to said heaterport and said bypass port.
 19. The valve of claim 14, wherein said valverotor has fluid passages formed therein to allow said inlet port to beset into fluid communication with said heater port while blocking flowto said radiator port and said bypass port.
 20. The valve of claim 11,further comprising a degassing port formed in said valve housing andsaid valve rotor has a fluid passage formed therein for setting saidinlet port into fluid communication with said degassing port when saidvalve rotor is in preselected rotational orientations relative to saidvalve housing.
 21. The valve of claim 20, wherein said degassing port isparallel to and radially offset from the rotational axis of said valverotor within said valve housing.